The Transgenic Mouse Core B Facility has four major aims: 1. To maintain breeding colonies of transgenic mouse lines and to provide cohorts of transgenic mice for studies proposed in Projects 1, 2 and 3 of this Program Project grant. 2. To establish C57BL6 congenic lines of the transgenic mice use throughout the study. 3. To generate new transgenic and knock-in mice carrying functional mutations to PARP. 4. To generate PARG knockout mice. The Transgenic Mouse Core B Facility will be a shared resource of the Program Project grant and will play a central role in our investigations in the pathogenesis of Stroke and Neuronal Injury.